Alloy You might see the word alloy described as a “mixture of metals”, but that’s a little bit misleading because some alloys contain only one metal and it’s mixed in with other substances that are nonmetals (cast iron, for example, is an alloy made of just one metal, iron, mixed with one nonmetal, carbon). The … Read more

Exothermic and endothermic reactions

Endothermic Reactions Endothermic reactions are those chemical reactions where energy is absorbed by the system from the surroundings mostly in the form of heat. The concept is applied in the physical sciences like chemical reactions where hear is converted to chemical bond energy by way of experiments. Common examples of endothermic reactions are cooking an … Read more

Acids and bases

Acid An acid is a substance which forms H+ ions as the only positive ion in aqueous solution. Examples:- Hydrochloric acid dissolved in water forms H+ and Cl– ions   HCl —> H+ + Cl–   Sulphuric acid dissolved in water forms H+ and SO42- ions   H2SO4 —>2H+ + SO42-   Nitric acid forms H+ and NO3– ions when dissolved in water   HNO3 —> … Read more

Global warming

Global warming is a term used for a gradual rise of atmospheric temperature and consequent changes in the radiation balance mainly due to human action leading to climatic change at different levels – local, regional and global. As per recent estimates, it has been found that  the surface air temperature over the past 100 years … Read more

Water Resources : Availability

  Water is a prime natural resource, a basic human need and a precious national asset. Planning, development and management of water resources need to be governed by national perspectives. India accounts for about 2.45 per cent of world’s surface area, 4 per cent of the world’s water resources and about 16 per cent of … Read more